[GHC] #11563: fvProv falls into a hole (instead of detecting missing type argument) (regression from -rc1 to -rc2)
#11563: fvProv falls into a hole (instead of detecting missing type argument) (regression from -rc1 to -rc2) -------------------------------------+------------------------------------- Reporter: j.waldmann | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- This program has an error (T is missing an argument) {{{ data T a ; class C t ; instance C s => C T }}} which makes 8-rc2 fall into a hole: {{{ /opt/ghc/ghc-8.0.0.20160204/bin/ghc -c Bug.hs ghc: panic! (the 'impossible' happened) (GHC version 8.0.0.20160204 for x86_64-unknown-linux): fvProv falls into a hole {ap6} }}} It is detected by 8-rc1: {{{ /opt/ghc/ghc-8.0.0.20160111/bin/ghc -c Bug.hs Bug.hs:1:40: error: • Illegal instance declaration for ‘C T’ (All instance types must be of the form (T a1 ... an) where a1 ... an are *distinct type variables*, and each type variable appears at most once in the instance head. Use FlexibleInstances if you want to disable this.) • In the instance declaration for ‘C T’ Bug.hs:1:42: error: • Expecting one more argument to ‘T’ Expected a type, but ‘T’ has kind ‘* -> *’ • In the first argument of ‘C’, namely ‘T’ In the instance declaration for ‘C T’ }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11563 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#11563: fvProv falls into a hole (instead of detecting missing type argument) (regression from -rc1 to -rc2) -------------------------------------+------------------------------------- Reporter: j.waldmann | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: 11520, 11516, | Differential Rev(s): 11399 | Wiki Page: | -------------------------------------+------------------------------------- Changes (by j.waldmann): * related: => 11520, 11516, 11399 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11563#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#11563: fvProv falls into a hole (instead of detecting missing type argument) (regression from -rc1 to -rc2) -------------------------------------+------------------------------------- Reporter: j.waldmann | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #11520, #11516, | Differential Rev(s): #11399 | Wiki Page: | -------------------------------------+------------------------------------- Changes (by j.waldmann): * related: 11520, 11516, 11399 => #11520, #11516, #11399 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11563#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#11563: fvProv falls into a hole (instead of detecting missing type argument) (regression from -rc1 to -rc2) -------------------------------------+------------------------------------- Reporter: j.waldmann | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #11520, #11516, | Differential Rev(s): #11399 | Wiki Page: | -------------------------------------+------------------------------------- Comment (by j.waldmann): compared to the related tickets that I found when searching for "falls into a hole", this one here * uses no language extensions, has short source code * is a regression (of rc2 w.r.t. rc1) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11563#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#11563: fvProv falls into a hole (instead of detecting missing type argument) (regression from -rc1 to -rc2) -------------------------------------+------------------------------------- Reporter: j.waldmann | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #11520, #11516, | Differential Rev(s): #11399 | Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): True; but #11520 has a complete diagnosis. I'll try the solution I propose there. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11563#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#11563: fvProv falls into a hole (instead of detecting missing type argument)
(regression from -rc1 to -rc2)
-------------------------------------+-------------------------------------
Reporter: j.waldmann | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler | Version: 8.0.1-rc2
Resolution: | Keywords:
Operating System: Unknown/Multiple | Architecture:
| Unknown/Multiple
Type of failure: None/Unknown | Test Case:
Blocked By: | Blocking:
Related Tickets: #11520, #11516, | Differential Rev(s):
#11399 |
Wiki Page: |
-------------------------------------+-------------------------------------
Comment (by Simon Peyton Jones
#11563: fvProv falls into a hole (instead of detecting missing type argument) (regression from -rc1 to -rc2) -------------------------------------+------------------------------------- Reporter: j.waldmann | Owner: Type: bug | Status: merge Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | typecheck/should_fail/T11563 Blocked By: | Blocking: Related Tickets: #11520, #11516, | Differential Rev(s): #11399 | Wiki Page: | -------------------------------------+------------------------------------- Changes (by simonpj): * status: new => merge * testcase: => typecheck/should_fail/T11563 Comment: Ha! One fix closes four tickets. Merge to 8.0 branch. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11563#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#11563: fvProv falls into a hole (instead of detecting missing type argument) (regression from -rc1 to -rc2) -------------------------------------+------------------------------------- Reporter: j.waldmann | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc2 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | typecheck/should_fail/T11563 Blocked By: | Blocking: Related Tickets: #11520, #11516, | Differential Rev(s): #11399 | Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: merge => closed * resolution: => fixed Comment: Merged to `ghc-8.0` as d0010d749f80b405f991e88e0e953a21d54a744d. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11563#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
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